In related arts, a coil is directly connected to a chip in an electronic device such as a smart card. When the smart card is placed in a radio frequency field, a chip circuit of the smart card consumes field energy to communicate with a card reader (such as Point of Sale (POS) terminal, Near Field Communication (NFC) mobile phone or the like). In practice, in order to save a size of the smart card, a battery is not generally set in the smart card. Therefore, an existing smart card generally does not have other power consumption components except the chip circuit.
With the development of the smart cards, there is a need to include other power consumption components in addition to the chip circuit in the smart card in related arts. For example, a display screen is set on the smart card for displaying information during a transaction process. In this condition, it is required to power the smart card. Therefore, it may be desirable to provide a power acquirement circuit in the smart card. The power acquirement circuit acquires electric energy from the coil. In this case, it may be unable to obtain optimal power-acquirement efficiency when the chip circuit and the power acquirement circuit share a common coil. However, adding a power acquirement coil may increase difficulty and cost of circuit designs, and also affects communication between the smart card and other devices. Therefore, a radio frequency carrier between the coil and the chip must be turned off when a common coil is used as the communication coil and the power acquirement coil. How to disconnect the radio frequency carrier between the coil and the chip is a technical problem to be solved in related arts.